Porphyry copper deposits are copper ore bodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Predating or associated with those fluids are vertical dikes of porphyritic intrusive rocks from which this deposit type derives its name.
What do copper deposits look like?
Copper ore looks like a greenish chunk of stone. Keep an eye on your antler pickaxe’s status bar while you work. If it degrades too much you’ll need to repair it at your workbench. And be careful while mining on a hillside, as chunks of copper ore may roll away before they’re collected into your inventory.
Where are copper porphyry deposits?
Porphyry copper deposits form in continental magmatic arcs along convergent plate-margin boundaries or in island-arc environments. The deposits are associated with subduction-related volcanic centers, although in some examples, they are thought to be associated with postcollisional volcanism.
Does porphyry contain copper?
Porphyry deposits are large (from 100 million to several billion metric tons [t]), low-grade (0.2–1.5 wt% copper, < 0.01–0.3 wt% molybdenum, and < 0.01–1 g/t gold; Fig.
What is porphyry used for?
Porphyry is prized for its great compressive strength and exceptional durability. For this reason it is now most commonly used as a paving stone.
What causes porphyry?
Porphyritic rocks are formed when a column of rising magma is cooled in two stages. In the final stage, the magma is cooled rapidly at relatively shallow depth or as it erupts from a volcano, creating small grains that are usually invisible to the unaided eye typically referred to as the ground mass.
How are porphyry deposits formed?
Porphyry deposits typically form in oceanic or continental arcs above subduction zones (Fig. 1). As the oceanic plate and overlying sediment subduct, increasing pressures expel water from the sediment, and hydrous minerals in the oceanic plate start to break down.
How do you check for copper deposits?
Look for igneous rocks. Igneous rocks are volcanic in origin, and copper is usually located in igneous rock formations that are surrounded by rocks that have been altered by volcanic pressure and high temperatures. These deposits are called porphyry copper deposits.
What characteristics are related to porphyry deposits?
Other common characteristics of the porphyry-type deposits include a large hydrothermal system dominated by magmatic ± meteoric fluids, pervasive hydrothermal alteration of host rocks, fracture-controlled ore mineralization, and association with breccias of diverse origins and variable degrees of mineralization.
Is porphyry A Phenitic or Phaneritic?
Examples of phaneritic igneous rocks are gabbro, diorite and granite. Porphyritic textures develop when conditions during cooling of a magma change relatively quickly.
How much does porphyry cost?
Walking, biking and driving on porphyry driveways is easy and smooth. Because it is a unique material, porphyry can cost $15 or more per square foot.
Is porphyry A rare stone?
Imperial Porphyry is arguably the rarest and most historically important stone in the world. It comes from only one source; a single mountain in Egypt that the Romans called Mons Porphyry. It is a purple, volcanic stone, very dense and fine-grained, with small white inclusions.
What are the products of porphyry copper deposits?
The major products from porphyry copper deposits are copper and molybdenum or copper and gold. The term porphyry copper now includes engineering as well as geological considerations; It refers to large, relatively low grade, epigenetic, intrusion-related deposits that can be mined using mass mining techniques.
What is anomalies in porphyry?
Anomalies can be very tightly defined using soil geochemistry and usually wet enough to allow you to site a drill hole. As with almost all ore deposit types porphyry targets need to be drilled eventually to quantitatively determine actual copper, gold and molybdenum values in the identified mineralization.
What is the size of a typical copper deposit?
On average these deposits can have a vertical and horizontal extent of 1-2 km and can range from tens of millions to a billion+ tons in size. While copper is generally the dominant metal, porphyry copper deposits can contain multiple accessory metals, such as molybdenum, gold and silver.
Where do porphyry deposits occur in the world?
Porphyry deposits occur in two main settings within the orogenic belts; in island arcs and at continental margins. Deposits of Cenozoic and, to a lesser extent, Mesozoic age predominate.
